Electrical Problems

[Sage]

I have a 1997 Chevy S10 with a 5-speed manual transmission. Recently, I have been having a lot of electrical problems. It all started with the fan for the heater which would shut off for a second and then start up again. Next, it started on the speedometer which would go haywire and say I was going 90 MPH when I was really only going 30 MPH. The next thing that went wrong was the entire truck would seem to have a power surge and the engine would just cut out. When it would happen, all the dash lights would dim and the radio would start making a static noise, and finally the engine would stall.
After encountering the engine problem, I looked under the hood and saw that the spark plug wires seemed to have been sitting against the headers, so I replaced those, the plugs, my air filter, and my fuel filter; basically I just gave the truck a tune up. For about a week everything seemed to be fine and working well again, but the original symptoms are starting up again. The heater is cutting out and now the headlights will actually turn off on me. So, I haven't been able to drive it at all, and I have been asking a few mechanics that I know what they think the problem might be and so far all I have gotten is that it may be a bad relay or a faulty ECM. If anyone has any ideas at all I would really appreciate the input.

[NEUMANNZZ]

maybe check your ground wires.

[Sage]

I checked the ground wires and they are in good condition. When I was looking around at the chassis ground, a loose nut on the back of the alternator caught my eye. Turns out that the nut that holds the wire ends onto the post on the back of the alternator was nearly off, so when I was hitting bumps and making turns, I would lose my connection. I tightened up the nut and haven't had a problem since, so I hope that it's fixed...seems logical to me.

[NEUMANNZZ]

good find. should be good to go.